Filter.



No! 885,393. .PATENTED APR. 21, 1908.

' B. J. SWEETLAND.

FILTER.

APPLICATION FILED JULIE. 1907.

* 2 SHEETS-SHEET 1.

' Noi 885,398. PATENTED APR. 21, 1908.

E. J. SWBBTLAND.

FILTER.

urmourox nun JULYQ, 1901.

' 2 sums-sum 2.

UNITED str'iifrias PATENT OFFICE.

' ERNEST SWEETLAND, OF GOLDFIELD, NEVADA.

' FILTER.

Specification of Letterslatelit.

Patnted April 21, 1908.

Application filed July 9, 1907. Serial N o. 382,961.

To all whom it may concern:

Be it known that I, ERNEST J. SWEETLAND, a citizen of the United States,residing at Goldfield, county of Esmeralda, State of Nevada, haveinvented'a new and useful Filter,

of which the following is a specification.

This invention relates to filters desi ned for the filtration of anyliquid where a l arge volume is to be handled, such as in the filtrationof a supply of water, for a city, but is more especial y designed forthe separation of slimes and solution in the treatment of ores by thecyanid process.

In the filtration of water for domestic pur- 15. poses where it isnecessary to filter through some medium, such as fullers earth,charcoal, etc., the machine is so designed that'this can be accomplishedwithout difficulty. In the treatment of ores by the cyanid rocess it iscustomary to separate the tai in s into two roducts for treatment, thesan s and the s imes. The slimes are treated by agitation in vats withcyanid solution, and when the values have been dissolved by agitationwith cyanid, the next step is to separate the solution from the residuesfrom which the values have been dissolved, and it is for that separationthat this machine is particularly designed. This slime is in such anextremely fine state of division that it is impossible to peroolate anyliquid through it at an economical rate without the assistance of eithera vacuum or pressure. The vacu-, um filters-now in .use have thedisadvantage that the acceleration is limited to the pressure of theatmos here, while in a pressure filter, under ,whicfi head thisinvention occurs, there is no limit to the amount of force 1 that can beused for hastening the operation.

specification I refer to ore in a state of ex tremely fine divisionmixed with liquid, forming a thin m ud, or sludge.

Qne object of the invention is to provide a maximum filtering area,whereby filtration can be accelerated by pressure, and enabling the useof both vacuum and pressure, if desired.

Another object is to admit. the slimes at the top of the filter deviceswhich prevents the tendency of the slimes to become mored'en'scat thebottom than at the top, as prac tice has shown that the natural tendencyof the slims is to settle or become more dense at the bottom whenadmitted to the receptaclefrom the bottom. 1

solved values contained wi In using the term slimes throughout this.

. 2 and 4, comprising an upward rectan Another object is to provide fordischargin the residue from the filter without manua labor and by thesimple manipulation of valves and without excessive waste of water.

Another object is to provide for depositing.

Another object is to dispense with employing water in discharging teresidue from the filter.

During the filtration process the residue forms as a cake on thefilterdevices, and another bbject is to cause this cake to form with anevendensity throughout regardless of its thickness, thereby promotingthe ease with which-the cakes are removed from the filter devices andinsuring that when wash water is applied the cakes will be accuratelyand evenly washed in all arts and the disll thus be removed with aminimum amount of washing solution.

The accompanying drawings illustrate the invention, and referrin thereto:Figure 1 is a side elevation of a filter with a portion at the rightside broken away. Fig. 2 is a sec tion on line x r Fig; 1. Fig. 3 is asection on linem 0: Fig. 2. Fig. 4 is a'front elevation of one of theframes shown partly in section. Fig. 5 is a perspective vlew partly insection and with thecanvas cover broken away to show the detailconstruction of a filter device. Fig. 6 is a view on line xjx Fig. 5.Fig. 7 is a view similar to Fig. 4, showinga modified form of frame. v

1 and 2 designate the main standards which are secured to' thefoundation and are connected with each other 'by a pair of tie rods 3.vSupportedon the tie rods 3 is a se ries'of frames 4, eachframe, as shownin F1 s.

portion terminating at the bottom wit an lnclined portion or wedgeshaped frame hav-- ing a straight portion 5. Each frame-4 on one side isprovided with a groove, and gaskets 6 are laid'in the grooves, to seal'the "oints between the frames, as clearly shownrn Fig. 1.- Each frame 4is provided with a pair of lugs 7 which rest upon the .two tie I ipe 9has opper '8 aValves 11 and 12 are rovlded 1n the respec tive pipes 9.The va ves- 11 and 12 connectrods 3, and all of the frames are thussupported ina vertical position, parallel with each. other. The frames4' are not all of equal length but are that when .assemble they twillform, as shown in Fig. 1, a bottom having two hopers 8. It'is obviousthat the number of frames could be increased or diminished to form moreor less hoppers 8, according as it may be desired to increase ordiminish the" capacity of the filter.

The three longest frames 4 at the center of-eac'h ho er 8 are of thesame length, as shown in 1g. 1, thus forming a flat surfacefor theattachment of a pipe 9, the upper end of which is flared and 0 ted tothe bottom of the frames 4. Each communication with its adj ace'ntthrough. passages 10 which are formed in the bottom of the associatedframes 4, as shown at the right in Fig. 1.

at the bottom with a horizontal pipe comprisin two sections 13 and 14which are unite by expansion joints 15, the section 13 having-a valve16and the section 14 having avalve 17.'

As shown in Fig, 1, at the right, the gasket 6 lies in'a groove in thestandard 2, while at the extreme left a head 18 receives a similargasket. The head '18 has a? pair of rollers 18 which rest upon the tierods3, and the head is thus supported in common with the frames 4, andall of the frames are held tightly compressed together .by means of ascrew 19 which is threaded in the standard 1 and has Y a wheel 20 on itsouter end for turning it to I produce the requisite pressure.

hole and annular grooves and askets 24 con- Each frame 4 is providedwith an ear 21 at the top, an ear 21 atone corner, and ears 22-and 23 atJ an intermediate point on the vertical bars of frame 4. Each ofsaidears has a central centric with the holes whic fit together similar tothe gaskets 6 of the frames, and

there are thus formed four longitudinal conduits, each being designatedin general 25, 26 27 and 28. Sus ended in a vertical position in eachinterme iate frame 4 is afilter device designated in general 29, andshown in de'-' tail in Figs. 5, 6 and 8. Each filter device preferablycomprises a number of strips of which wood or thin boards" 30 having aseries of verticallongitudinal grooves 31, the boards being tiedtogether edge to edge by a number of bolts 31, and a pipe 32 extendsalong the bottom of the boards 30, the pipe 32 being provided with aseriesof perforations 33. The lower edges of boards 30 are formed with aconcave recess to receive the upper portion of the ipe 32, and thatportion of the pipe 32 lies below the boards 30 is covered with a wirescreen 34, the object of which is to facilitate the passage of thefiltrate into the pipe 32. Canvas 135 extends around the graduated inlength so .to the upper end provided with a test-cock 43.

block and over the wire screen 34,- andyis firmly sewed all around theedges of the slab formed by the corrugated boards so that no liquid canpass from the main chamber of the filter into the pipe 32 without firstpassing through the canvasboards 30 and engage hooked shaped lugs 37which are cast integral with each frame 4 at each upper corner thereof.A valve chamber 38' is formed in the frame 4, as shown in Fig. 2, andcommunicates with the conduit 28 and a valve '39 is provided for closingcommunication between the conduit 28 and pipe 32.. A nipple 40 isscrewed in the valve chamber 38 and a piece of flexible Hooks 36 areattached of the slab formed by the v tubing 41 connects the nipple 40with the adjacent end of the pipe 32. The flexible tube 41 permits thelower end of. the filter device 29 to swing slightly, for a purposehereinafter described.

valve chamber 38is a drain port 42 which is a test-cock on each framewhich carries a filter device it is possible, by drawing a-glass of theliquid from each filter device through the test-cock, to easilyascertain if any of the By providing.

Communicating with the filter devices are leaking and to locate theparticular one which is leaking. Without this means it would benecessary to take the entire machine a device was at fa t, and the leakwere small it would even then be very difficult to locate the trouble.The. valve 39 is kept closed untilit is found convenient to replacethefaulty filter device, and this prevents the admission art't'odiscover which filter of any turbid-liquid} to thefiltrate from theother filter devices. With this provision, however, the removal of afaulty filter'device and its replacement by a new one is easily accomlished all? that necessary being to slac oif the screw 19, disconnectthe flan ed pipes 9, and by remove the articular frame which carries theleaking ter device. The test-cock 43 and associated valve chamber 38 andvalves 39 are provided in alternate frames 4, thus as shown in Fig: 1,there is a test-cock on the nearest side of every fifth frame, while onthe other side of the machine there are also testcocks on every fifthframe, each of which frames are midway between each two testcocks on thenearest side shown. Communiadapted to discharge wash water against themeans of a block and tac e .two adjacent surfaces of the two filterdevices between'which that frame lies. 'Each of these frames 4, as shownin Fig. 4, is also provided with a flaring pert 51 which communicateswith the conduit 25 in the top ear 21, and is adapted to discharge washwater therethrough in addition to that discharged by the pipe 49, ifnecessary. But it should be understood that the main object of thisconduit and its arts is for the admission of the turbid 'li ui to befiltered to the main chamber. T e car 21 of each frame 4 is providedwith an eye 52 by means of which the frame may be lifted. Pipes 53 and54 com- 5 municate a'ttheir respective ends with the conduit 25, thedpipes 53 and 54 beingres ectively provi e with valves 55 and 56. ldi cs5.7 communicate with the ends of condult 26,- the pipes 57 beingprovided with valves 58. A prpe 59 is screwed to the frame 2 andcommunicates-with the interior of the filter chamber for the admissionof air into the chamber or for special purposes and is provided with avalve 60. A pressure age -61 is connected by a pipe 62 with the Achamber.; 'A pipe 63- communicates with the "filter chamber at. thelower portion thereof, as shown in Fig. 1,. and is provided with a valve64.-

The slimes having been duly agitated are forced in to the filteringchamber throu h pipes 13 and 14 past valves 11 and 12 to l the filter.chamber and expel the air therefrom,'the airv escaping during thisoperation past the valve 55' which has been opened. As

soon as the liquid appears at valve .55, showing that all air has beenexpelled, the valve 4 is closed, and the pump continues to operate. Assoon as the air is expelled, it is advisable to admit the slimes throughthe pipe 54. As

there is no way for the liquid to escape exce t throu h the pores of thefilter devices 29, t e

' cleariquid passes into the pipes32. of the filter devices filte'rin.through the canvas 35 and flowing down t ough grooves 31 and througherforations 33 into the pipes 32, the clear liquidpassing from all ofthe pi es 32 into the conduits 27 and 28, valves 39 e 'ing opened andclear liquid being conveyed so from these conduits by ipes 44'and 45.The

solid matter containe in the slimes is deposited in,'the form of a cakeon the surface of the canvas of the filtering devices 29. In umping theslimes into the filtering chamr from the bottom it has been found bexperience that the liquid becomes'more ense toward the bottom of thechamber than at the to making a tendency for thecake to form t 'ckertoward the bottom than at. the

' o top. To'overcome this difficulty the pipes 53 and'54 have beenprovided which connect with the conduit. 28. When the filtering chamberis filled, valves 11 and 12 are closed and the slimes are admittedthrough pipe 54 5 and pass into the conduit 25 and are introter and 54.

duced into the filtering chamber through the ports 51, whereby theslimes enter between each pair of filter devices 29.

Should a take, in building up, become thicker in some parts, than inother parts, the thicker parts being more dense Wlll retard filtrationthroughthem and the filtration will proceed at a more rapid rate throughthe thinner portions and thus deposit more residue on the thin portionsand build them up even with the thicker portions, and thus an eventhickness and density of the cake is automatically maintained.

' As the pump continues operation, the slime cakes increase in thicknesson the canvasof the filter devices until they are an inch or an inch anda half in thickness. The thickness being regulated by the density of theresidues deposited on the canvas, the thickness of which is judged bythe pressure indicated by the gage. Then the valves 11 and 12 are openedand the pump having been sto pad the liquid is Qallowed to run out ofthe 0 am? admitting compressed air through pipes 53. It will beunderstood that these slime cakes are heavy, and, as they adhere to thecanvas of the filterin devices in a vertical position, their naturaltendency is to fall ofi during this operation if some force did notholdthem there. They may be held there in two ways; first, by theadmission of com-. ressed air through pipe 53 which would orm a ressurein the chamber. .But the preferable way is to connect pipe 45 with avacuum of four or vve inches durin the time the slimes are running out.After the slimes 'have been removed the next step is to remove from theslime cakes the dissolved values which are contained therein. It will beunderstood that the cyanid solution which so far has been filtered fromthe slimes which at this time is contained in the cakes also containsgold in the same amount; To recover these values it is customary to washthese slimes by displacement. This is accomplished by opening valve 55and admitting wash water through'the pipes 13, 14 and pipes 9 into thechamber, and as soon as the water appears at the valve 55,'show1ng thatthe chamber is filled, this valve is closed while the pump continues tooperate, pumpin the wash water into the chamber through va ves 11 and12. As the wash water has no means of escape from thechamber, and thepump continues in operation, the wash water passes through the slimecakes into the mner chambers of the filter devices gndthrough theperforations 33 into the pipes 32 and out ump and maintain a vacuumthrough pipes 44 and 45; This eration is continue until tests made on te effiuent solutionshow that the values have all been removed from theslime cakes, and the next step is to draw off the remaining wash waterthrough the valves 11 and 12 and return it to the receptacle from whichit came.

As soon as the chamber is empty of wash water and under no pressure, novacuum beinterior of half of the filter devices.

' the hoppers 8'which form the bottom of the chamber, and the cakes lietherein in the.

form of a thick mud about seventy per cent. solid. The filter devicesbeing flexibly connected with the conduit 28 allows them a slight swin'ng motion as the cakes fall ofi, and the ca es are thus prevented frombecoming wedged between the filter devices,

which would be the cas if the filter devices 1 were rigidly connected.The valve 11 is into the ,presse through then 0 ened and valve 17closed, and comairis admitted to the chamber ipe 54 which forces the mudin the hopper 8 out through the valve 11 J i e 13 and out past the valve16. When lef fi hand hop er 8 has been'emptied valve 11 is closed an'valve 12 is opened, and as the chamber is still under air pressure themud in the right hand hopper 8 is forced out through valve 12 andthrough pipe 14 to any convenient point. The filter is then in conditionto be refilled with slimes and the en- 'left han tire operationrepeated. Note that this operatlon has disc arged the residues from onlyhalf of the blankets; and must be repeated, admitting air through pipe44 to disengage the cakes on the blankets connected to-this conduit, itbeing understood that these were held in place by vacuum while theothers were discharged. The object of thisis to avoid'overcr'owding thehoppers with mud. In case the cakes are thin all 'of theblankets may bedischarged at once by admitting air or water through pipes 44 and 45ingother liquids, for eX'amp e,

simultaneously.

- While the process filtering ofshmes, itshouid be understood thatthe-machine may be em loyed for filter the juice in a sugar factory orthe water supply for a city,

.in which latter case, .a. suitab e amount of filtering material, forexample, fullers earth, clayor carbon may be placed in the main chamberand caused-to form in cakes ,ont'he filtering devices, and "after thecakes have formed and the water to be filtered is passed through themachine/it is filtered from all described 'has been the solids,obnoxious gases, or deleterious substances. At intervals the cakes'offiltering material which in use have accumulated the impurities from thewater may be discharged from the filter device similarly to the mannerinwhich the slime cakes are discharged, and

the filtering cakes may again be reformed of fresh material.

By the arrangement of the filter blankets in alternate frames 4 it ispossible to discharge the residue from half the filter blankets at atime, and enable the hoppers'to be .made smaller than would be necessaryif all were discharged at once. Under certain con ditions it isadvisable to drop the cakes from the filter device before the chamber isemptied of wash water. In that case the mud dropping from the filterdevices goes to the bottom of the hoppers, while the wash water. whichremains at the top of the chamber is recovered by opening valve 64through which it is allowedto return to its receptacle.

If it is desired to filter constantly any li'q uid, such as the supplyof water for a city, or in any case where constant filtration isnecessary and the intermittent discharging of the filter would interferewith the operation, 7

er being it can be done as follows: The cham already filled and the airhaving been expelled, the pump is kept running until the pressure on puming against considerable resistance whic indicates that cakes ofconsiderable thickness has been'formed. By now apply: ing water undera'pressure greater than is indicated by the pressure gage through thethe gage 61 shows that it is conduit 27 the'result is to cause the cakeson the filter devices connected with the conduit 27 to fall into thehoppers. As soon as pressure is removed from conduit 27 'filtrationagain continues as before. Then water under pressure is. admitted to theconduit 28 which causes the cakes onthe filter devices connected withconduit28 to fall as before.

When operating under such conditions the valves 11 and 12 would be leftslightly open,

so that the sediment in the bottom of the press would be continuallydischarged by the draulic pressure onthe interior of the c amber. Thismethod of constant filtration would not be used when it was advisable touse fullers earth or other material as a filtering medium in additiontothe canvas.

afiord means fonsimultaneously washing all of the filter blankets freefrom any material of sticky nature. which mayrhave adhered thereto'ynothaving dropped off with the chamber.

The object of providing the pipes 49 is to v a chamber comprising aaduatedthe chamber, and filtering means in the 2. In a filter,.a chambercomprising a series 7 of frames each havin .a rectangular upper meansfor holdin portion and wedge s aped, lower portion,

the frames closely together, the frames eing graduated in length withtheir upper ends in line -to form a plurality of hoppers in the bottomof the chamber, and filtering means in the chamber.

3. In ,a filter, a chamber comprising a series of frames each having arectangular upper portion and wedge shaped lower portion, means forholding the frames closely together, the frames being graduated inlength with their upper ends in line and forming a hopper in the bottomof the chamher, and filterlng means in the chamber.

4. In a filter, a laminated chamber comprising a series of frames heldtogether, each frame having a'plurality of hollow ears, each ear havinga passageway to the inside of the .lframe, thereby forming a pluralityof conduits along the chamber which have com- -munication with thechamber, filtering means inside the chamber, and test-cocks in certainears communicating with the interior of the ears. i

' 5. In a filter, a laminated chamber comprising a series of frames heldtogether, each frame having a plurality -of hollow ears, certainears'having assageways to the inside of the frame, thereb a conduitsalong the. chamber which have communication with the chamber, "apluralfiltering device-being supported by a frame, a connection from thepassageway of the frame to the filter, and a valve for shutting offcommunication of the filter with the hollow ear and conduit associatedtherewith. 40

6-. In a filter,'a laminated chamber com prising a series of frames heldtogether, each frame having a: plurality of hollow ears,

certain ears having assageways to the insideof the frame, there yforming a plurality of .conduits along the chamber which havecommunication with the chamber, a pluralit of filtering devices in thechamber, eac

filtering device being supported by a frame, a

connection from the passageway of the frame to the filter, and a valvefor shutting off communicati'on'ofthe filter withthe hollow.

ear and conduit associated therewith, the top ears of certain frameshaving a flaring port communicating with the interior of the chamber; a

1.7. In a filtena laminated chamber comprising a series of frames heldtogether, each ame having a plurality of; hollow ears, certain earshaving assageways to the inside of the frame, there y forming aplurality of conduits .along the chamber which have communication withthe chamber, a luy-forming a plurality of screen an pipe. 4

' theframe to the filter, a valve for shutting off communication of thefilter with the hollow ear and conduit associated therewith,- the topears of certain frames having a flaring port communicating with theinterior of the chamber, and perforated pipes in the latter framescommunicating with a side conduit. 8. In a filter, a chamber comprisinga series of frames each having a rectangular upper portionand wedgeshaped lower portion, -.means for holdin the frames closely together,the frames icing graduated in length with their upper ends in line toform a plurality. ofhoppers in the bottom of the chamber, filteringmeans in the chamber, a pipe below the chamber comprising two sectionsunited by an expansion joint, pipes .from said respective sections tothe respec. tive hoppers, a valve in each of said latter pipesyand outervalves in each of said sections.

9. In-a filter, achamber comprising a series of frames held together andsealed at the joints, andfiltering devices suspended from alternateframes;

1(k In a filter, a chamber comprising a series of frames held togetherand sealed at the joints, and filter-ingdevices suspended from alternateframes, conduits along both sides of the chamber, alternating filterdevices being in communication Wltll one conduit and the interveningfilter devices gem-g in communication with the other conuit.

11f In a filter, a chamber comprising a series of frames held togetherand sealed at the joints, and filtering devices suspended from alternateframes, a conduit along the side of the chamber and flexible connectionsbetween filter devices and the conduit permittin the filter devices toswing slightly.

12. In a filter, a ch'ambercomprising a.

series of frames detachably held together and sealed at the joints, andendent filter devices in the chamber detac ably hung to the frames.

13. In a filter, a filter device comprising a plate with verticalcorrugations, a perforated pipe along its lower edge, awi're screenoverthe 'pe, and canvas over the plate,\

14. In a filter, a filter device comprising a plate formed of aplurality of boards arranged edge to edge and tied with bolts, theboards haying vertical grooves and a concave recess in their loweredges, a perforated pipe seated in the recess, a wire screen around thepipe, and canvas around the boards, screen and plpe. a

\ 15 'In a filter, a filter device comprising a plate formed of aplurality" of boards arranged edge to edge and tied w th bolts, theboards having vertical grooves and a concave recess in their loweredges, a perforated pipe seated in the recess, a wire screen around thepipe and canvas around theboards, screen'and pipe, a chamber comprisinga series of frames held closely together and sealed at the joints, eachframe having a pair boards having vertical grooves cave recess in theirlower edges, a perforated of lugs, and hooks on said boards engaging thelugs on the frames for supporting the filter devices.

16. In afilter, a filter device comprising a plate formed of a pluralitof boards arranged edge to edge and tie with bolts, the and a con pipeseated in the recess, a wire screen around the pipe and canvas aroundthe plate, screen and pipe, a chamber comprisingl a series of framesheld closely together an sealedgat the joints, each'frame having a pairlow ear having a of lugs, hooks on said boards enga mg the lugs on theframesfor sup orting t e filter devices, hollow ears on the ames, eachholsage, and a flexib e tube'co'nnectin each nipple with the pipe oftheassociate vice.

- 17. In a filter, a filter device comprising a plate formed of aplurality of boards arranged ed e to edge and tied with bolts, the

boards h ving vertical grooves and a concave recess in their loweredges, a perforated pipe seated in the recess, a Wire screen around thepipe and canvas around the boards, screen and pipe, a chamber comprisinga series of frames held.closely together and .sealed at the joints, eachframe having a 18. In afilter, a laminated chamber com prising a seriesof frames, each frame havinga hollow car oneach side, a hollowear on anupper corner and a hollow car on the top, said hollow ears forming fourconduits, horizontal perforated ipes in alternate frames connecting withthe associated corner ear,

the top ears of the latter frames having downwardly flarin ports, afilter device hung from eachof t e'latter frames, the side ears of theintervening frames having passages in communication with the. filterdevices, and valves for controlling said passages. c

19. .In a filter, a chamber comprising a series of frames held'togetherandsealed at the joints, filtering devices suspended from cer-. tamframes, conduits along both sides of the chamber, said filter devicesbeing in comassage, anipple in the pas filter desssgseemunication withone conduit, and interven-- ingfilter'devices in communication with theother conduit.

20. In a filter, a laminated chamber comrising a series of frames heldtogether, each rame having a plurality of hollow ears, cer

.tain ears having passageways to the inside of the frame thereby forminga lurality of conduits along the chamber w ich have'communication withthe chamber, a pluralit of filtering devices in the chamber, each teringdevice being supported by a frame, and a connection from the passagewayof the frame to the filter.

21-. In a container for filters the body of which com rises a series offrames held toether to orm a continuous chamber, said rames havingalining o enings which forma conduit along said cham er, and a pluralityof filters within said chamber communicating with the conduit.

22. A filter, the body whereof comprises a series of frames clamped toether, to form a filtering chamber, filtering evices in the upperportion of said chamber, and an 0 en ongltudinal space through said chamer adapted to receive residues falling from said filter devices. 1

- 23. In a filter, a chamber comprising a seriesof frames arranged sideby side, filterin means in the upper part of said chamber, am the lowerspace of the chamber being continuous and unobstructed by the filtermeans. Q95,

24. Ina filter, a series of frames held together to form a singlecontinuous chamber, and filtering means in the upper portion of thechamber leaving the lower portion unobstructed.

25. In a filter, a series of frames held together side by sideito form acontinuous chamber having laminated walls, and filter devices in theupper part, of said chamber, the spaces between the filter devices beingunobstructed and the space below the filter devices being unobstructedand in full communication with the filter devices.

26. A filter, the body whereof comprises a series of frames clampedtogether, each' frame having a passageway through one of" the wallsthereof, said assa' eways alining to form a continuous con uit,filtering means in the upper portion of the chamber adapted to drain'thefiltrate into'said conduit, and an open longitudinal-space between saidfiltermeans and the lower walls of the chamber. ILtGStIIIlOIIY where f,I have hereunto set' my hand at Los Ange es, California, this 2d day ofJuly l907. 1

. ERNEST J, SWEETLAND. In presence ofv I GEORGE T. HAcK Y,

FRANK L. A,

